Rust preventive concrete form release oil

ABSTRACT

AN OIL COMPOSITION USEFUL AS A RUST PREVENTIVE ON STEEL CONCRETE FORMS COMPRISING 84-92 VOLUME PERCENT NAPHTHENIC BASE MINERAL OIL HAVING A VISCOSITY OF 40100 S.U.S. AT 100*F., 4-8 VOLUME PERCENT DIMERIZED LINOLEIC ACID AND 4-8 VOLUME PERCENT LECITHIN. THESE COMPOSITIONS SHOWED NO CORROSION ON TEST PLATES IN A HIGH HUMIDITY CABINET AT 140*F. AFTER 9 DAYS.

United States Patent RUST PREVENTIVE CONCRETE FORM RELEASE OIL Howard M. Rue, Media, Pa., assignor to Sun Oil Company of Pennsylvania, Philadelphia, Pa. No Drawing. Filed July 3, 1972, Ser. No. 268,430 Int. Cl. C23f 11/10 U.S. Cl. 252-389 A 6 Claims ABSTRACT OF THE DISCLOSURE An oil composition useful as a rust preventive on steel concrete forms comprising 84-92 volume percent naphthenic base mineral oil having a viscosity of 40- 100 S.U.S. at 100 F., 4-8 volume percent dimerized linoleic acid and 4-8 volume percent lecithin. These compositions showed no corrosion on test plates in a high humidity cabinet at 140 F. after 9 days.

BACKGROUND OF 'IlI-IE INVENTION (1) Field of the invention This invention relates to a composition for the rust prevention of steel concrete forms.

(2) Description of the prior art In the construction industry steel concrete forms are generally coated with corrosion-resistant coatings during storage and in use. These coatings must not only prevent rusting of the concrete form but also must prevent the subsequent unsightly rust staining of the concrete and prevent the adhering of the concrete to the form during drying and curing. Currently used for this purpose are compositions of oils containing fats, fatty acids such as tall oil, containing mineral oil and kerosene. The major drawback with these compositions is that the protective life is very short particularly in high humidity environments.

SUMMARY OF THE INVENTION The compositions of the present invention are economical, are easily applied and have improved protection life. Furthermore, no appreciable rust staining has been noted on concrete using these compositions even in high temperature and high humidity conditions.

The rust preventive compositions comprise 84-92 volume percent naphthenic base mineral oil having a viscosity at 100 F. of 40-100 S.U.S. to which is added 4-8 volume percent dimerized linoleic acid and 4-8 volume percent lecithin.

DESCRIPTION OF THE PREFERRED EMBODIMENT The base oil to which the other materials are added is naphthenic oil preferably a distillate oil which has been derived from a naphthenic based crude oil, i.e., a crude oil having a viscosity gravity constant of about 0.88 and having a viscosity at 100 F. of 40 to 100 S.U.S. preferably 40 to 60 S.U.S. In a preferred embodiment to this oil is added 5 volume percent dimerized linoleic acid and 5 volume percent lecithin.

The dimerized linoleic acid has the structural formula The term lecithin refers to a mixture of acetone insoluble phosphatides, including phosphatidylcholines and cephalin together with other substances such as carbohydrates, glyceride oil and sterols that occur with the phosphatides. Examples of suitable lecithins are those derived from corn, peanut, rapeseed, cotton-seed and ice caster-seed but preferably from soybean. See Table I below for a typical commercial lecithin.

Any suitable procedure may be used for incorporating a solution of dimerized linoleic acid and lecithin into the base oil. Generally the desired quantity of dimerized linoleic acid is dissolved into the naphthenic oil at 70- 150 F. followed by the addition of lecithin using a simple propeller type of mixer. No further treatment is required and the composition may be used immediately for practicing the invention or may be stored for future use.

The following examples are submitted to show the manfacture of the rust preventive concrete form release oil composition.

EXAMPLE I To a base naphthenic oil having a viscosity of about 40-100 S.U.S. at F. was added a solution of 5 volume percent of dimerized linoleic acid and 5 volume percent lecithin. The ingredients were blended with mild agitation at room temperature until solution was formed.

Examples A, B and C are comparative.

Example A This is a comparative example omitting dimerized linoleic acid from the formulation as shown in Example I.

Example B This is also a comparative example omitting lecithin from the formulation as shown in Example I. This solution is not homogeneous.

Example C In this comparative example the sodium petroleum sulfonate was substituted for lecithin.

By way of illustration of the invention, a series of comparative tests were conducted in the Cleveland condensing humidity cabinet manufactured by The Q-Panel Company, Cleveland, Ohio, and indicate the effectiveness of the unique rust preventive concrete form release oil composition. A panel of cold rolled carbon steel was coated #by dipping with the respective coating formulation. The panel was then placed into the Cleveland condensing humidity cabinet where one side of the panel was exposed to an atmosphere of 100% humidity at 100-120 F. and the other side was at ambient temperature and humidity.

TABLE II Time (days) Condition of panel Do. Light rust.

Mi i- G9 Patented Nov. 27, 1973 These results show that the unexpected synergistic combination of this invention provides a superior rust preventive concrete form release oil.

Although the invention has been described in considerable detail with reference to certain preferred embodiments thereof, it will be understood that variations and modifications can be effected without departing from the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

1. An oil composition useful as a rust preventive on steel concrete forms comprising 84-92 volume percent naphthenic oil having a viscosity of 40-100 S.U.S. at 100 F., 4-8 volume percent dimerized linoleic acid and 4-8 volume percent lecithin.

2. An oil composition according to claim 1 containing 90 volume percent naphthenic oil having a viscosity of 40-60 S.U.S. at 100 F.

3. An oil composition according to claim 1 containing 5 volume percent dimerized linoleic acid.

4. An oil composition according to claim 1 containing 5 volume percent lecithin.

References Cited UNITED STATES PATENTS 3,462,358 8/1969 Mills et a1. 20814 3,617,473 11/1971 Lipscomb 20814 3,661,605 5/1972 Rubin et a1. 117-167 3,705,109 12/1972 Hausler et al. 21-2.5 R

LEON D. ROSDOL, Primary Examiner I. GLUCK, Assistant Examiner US. Cl. X.R. 

